1,2-Dibromoethane → 3-(3,4-Dimethylbenzoyl)-2-methylpropionaldehyde ethylene acetal

HRID 1415827Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1415827
BrCCBr.[Mg].[CH2:6]1[O:14][CH:9]([CH:10]([CH3:13])[CH2:11]Br)[O:8][CH2:7]1.CON(C)[C:18](=[O:27])[C:19]1[CH:24]=[CH:23][C:22]([CH3:25])=[C:21]([CH3:26])[CH:20]=1.[Cl-].[NH4+]>O1CCCC1>[CH2:6]1[O:14][CH:9]([CH:10]([CH3:13])[CH2:11][C:18](=[O:27])[C:19]2[CH:24]=[CH:23][C:22]([CH3:25])=[C:21]([CH3:26])[CH:20]=2)[O:8][CH2:7]1

Komponenten

7

Edukt 5

HCID 78391,2-DibromoethaneHCID 25517Ammonium ChlorideHCID 5462224MagnesiumHCID 143837522-(1-Bromopropan-2-yl)-1,3-dioxolaneHCID 14973055N-Methoxy-N,3,4-trimethylbenzamide

Produkt 1

HCID 218628313-(3,4-Dimethylbenzoyl)-2-methylpropionaldehyde ethylene acetalAusbeute 39 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel2×

Versuchsvorschrift

0.29 ml (3.4 mmol) of 1,2-dibromoethane was added to a suspension of 1.66 g (68.1 mmol) of magnesium in 5 ml of anhydrous tetrahydrofuran under a stream of nitrogen. 9.96 g (51.1 mmol) of 3-bromo-2-methylpropionaldehyde ethylene acetal [prepared as described in step (i) above] were then added dropwise to the resulting mixture, whilst ice-cooling, after which the mixture was stirred for 1 hour. A solution of 6.58 g (34.1 mmol) of N-methoxy-N-methyl-3,4-dimethylbenzamide in 30 ml of tetrahydrofuran was then added dropwise to the mixture, and the resulting mixture was stirred, whilst ice-cooling for 1 hour. A saturated aqueous solution of ammonium chloride was then added to the mixture, and the resulting mixture was extracted twice with ethyl acetate. The organic extracts were combined and washed with a saturated aqueous solution of sodium chloride, after which they were dried over anhydrous magnesium sulfate and concentrated by evaporation under reduced pressure. The residue thus obtained was applied to a silica gel chromatography column and eluted with a 6:1 by volume mixture of hexane and ethyl acetate, to give 3.26 g (yield 39%) of the title compound as a colorless oily substance.

Aufarbeitung

  1. temperaturecooling
  2. stirringthe resulting mixture was stirred, whilst ice-
  3. temperaturecooling for 1 hour
  4. extractionthe resulting mixture was extracted twice with ethyl acetate
  5. washwashed with a saturated aqueous solution of sodium chloride
  6. dry with materialafter which they were dried over anhydrous magnesium sulfate
  7. concentrationconcentrated by evaporation under reduced pressure
  8. customThe residue thus obtained
  9. washeluted with a 6:1 by volume mixture of hexane and ethyl acetate

Quellen und Nachweise

ORD-Eintrag
ord-0f88ab90ee4946f490b129062cec3d03
Quelldatensatz
uspto-grants-1999_06
Patentnummer
US05908858

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